Auxiliary electric power apparatus for tractors



Jan. 1 .1, 1947. c. w. MOTT 2,414,602

AUXILIAR I ELECTRIC POWER APPARATUS FOR TRACTORS Filed Oct. 28, 19444'SheetS-Sh8et l Jan. 21, 1947.

c. w. MQTT 2,414,602 AUXILIARY ELECTRIC POWER. APPARATUS FOR TRACTORS 7Filed Oct. 28, 1944 4 Sheets-Sheet 2 if r;- ::1 R a 111:: ::J A I Q Q nR BIN kg '4} M n wh Q N Q R n z- '2; O 2 J Q Q m n v; s 1

K b N r \9 Q Q (Q L w 1 c. w. MOTT 2 AUXILIARY ELECTRIC POWER APPARATUSFOR TRACTORS Jan. 21, 1947.

Filed Oct. 28, 1944 4 Sheets-Sheet 3 C(W. MOTT Jan; 21, 1947.

AUXILIARY ELECTRIC POWER APPARATUS FOR TRACTORS Filed oci. 28, 1944 4Sheets-Sheet 4 Patented i s. 21, 1941 AUXILIARY ELECTRIC POWER APPARATUSFOR TRACTORS Carl W. Mott, La Gran national Harvester C New Jersey 14Claims. 1

This invention concerns apparatus utilizable as a'power lift upontractors or the like and relates more particularly to such an apparatusadapted to receive driving force from an electric starting motor for thetractor engine.

The present invention is especially suited for use upon small tractorssince the power required for lifting and adjusting the correspondinglysmaller and lighter soil-working tools therefor does not exceed thatattainable iroma storage battery of a desirable capacity for servingstart-- ing, lighting and ignition systems of the vehicle. cumulatively,these manifold uses for a generator-battery electric system economicallyjustify its installation upon the small tractor. While an electricstarting motor is a desirable convenience, the cost of this motortogether with the battery .and other accessory parts 01' the electricsystem. in comparison to the small tractor itself, have heretoforecaused this auxiliary equipment to be regarded more or less as a luxury.When, however, it becomes possible to employ a tool ge, Ill., assignorto Interompany, a corporation of Application October 28, 1944,Serial No.560,808

in either direction an amount correlated with the amount the manualcomponent is moved or adjusted.

The above and other desirable objects, capabilities and advantagesinherent in and encompassed by the invention will become apparent fromthe ensuing description and the drawings wherein:

Fig. 1 is a side elevational view of a tractor having one embodiment ofthe invention installed 1 thereon;

litter and adjuster effectively powered by a generator-battery electricsystem, installation of the system is economically justified, and use ofthe electric starting, lighting and ignition equipment becomespracticable.

A general object of this invention i the provision of an inexpensiveelectrically energized auxiliary power device for adjusting toolsassociated with a tractor. Electrically energizing the device trom astorage battery on the tractor makes it possible for operationirrespective of whether the tractor engine is running.

Another object is the provision of an electrically energized auxiliarypower device controllable to selectively crank the tractor engine or tooperate tools'or the like.

Another object of the invention is the provision of such an auxiliarypower device carried on an intermediate body portion of the tractor andembodying a transverse rock-shaft, an electric motor, and gearingselectively disposable to connect the motor in driving connection withthe rockshaft or with the engine starting gear. This gearing preferablyincludes alternatively driven countershatts extending fore and aft ofthe tractor and respectively connected with the engine starting gear andthreaded to operate a travellug nut which is drivingly connected withthe rock-shaft. I

Another object is the provision of an electric clrcuitcontrol for themotor whereby a manually adjustable component determines the direction01 motor operation, and a motor-driven component causes the motor tostop after operation Fig. 2 is an enlarged view showing the midportionof the tractor body and the device mounted thereon, with a side wall ofits casing broken away for illustrating shafting and gearing therein,which shaiting and gearing are viewed as indicated by the section line2-2 in Fig. 3;

Fig. 3 is an end elevational view of the device taken on the line 3-3 ofFig. 2;

Fig. 4 is a wiring diagram illustrating a system of electric circuitconnections which may be employed in the device;

Fig. 5 is a fragmentary side elevational view of a modified form ofelectric circuit control utilizable with the device; and

Fig. 6 is a view taken on the line 6-8 of Fig. 5.

With continued reference to the drawings in Fig. 1 there is shown atractor including a body l0 wherein there is a front portion ll carryingan engine l2, a rear portion l3 carrying laterally spaced tractionwheels I, and a mid-portion l5 upon which the device constituting thepresent invention is mounted. The device, as can be seen from Figs. 1,2, and 3, includes a rock-shaft I! having arms I! upon opposite of itsends which are at opposite sides of a casing l8, and which arms H are tobe rocked or oscillated with the shaft IQ for producing endwise movementof tooloperating rods l9. It is one purpose of the present invention toprovide manually controlled power-operated means for causing therock-shaft l6 and the arms I1 to rock in either direction coordinatelyin direction and amount with the fore and aft pivotal movement of alever M which rotates about a stub shaft 22 which is shown in Fig. 2.Movement of the lever 2| is con-v The armature shaft 34 of the motorprojects forwardly into th casing l8 and is splined for constraining agear 35 to rotate therewith while permitting this gear to bemovedendwise of the shaft. Endwise movement of the gear 35 is accomplishedbya shifter fork 3G cooperable with a groove 31 in the hub of the gear andmanually rockable with a shaft 38 which carries a gear shifting lever 39upon a portion thereof externally of the casing.

Shiftable gear 35 is shiftable into the position shown where it mesheswith a gear 9| or to a more rearward position where it meshes witha gear42. When the gear 35 is meshed with thegear 4|, it is operable uponenergization of the motor 27 to rock the rock-shaft l6 as will presentlybe described, and when the gear 35 is meshed with the gear 42, it isoperable upon energization of the motor for driving the starting gear 43of the tractor engine.

Gear 42 is constrained for rotation with an engine-starting gear'driving shaft 44.j'ournaled at opposite of its ends in the rear andfront walls of the casing I8. An axially notched collar 45 is secured tothe front end of the countershaft 44 by a pin 46 in such a fashion thata forward portion of this collar projects forwardly beyond the end ofthe countershaft. A pinion shaft 41 journaled in a flanged bearingmember 48 also has an axially notched collar 49 secured thereto by apin,5|

' in such a manner that the back end of this collar projects rearwardlyfrom the rear end of the shaft 41 in opposed coaxial relation with thecollar 45. A yieldable universal articulate driving connection isestablished between the collars 45 and 41 by a helical spring 52 havingradially inturned end portions 53 respectively projecting into the axialgrooves 45' and 49' of the collars. The flanged part 54 of the bearing48 is secured to shown) of a traveling nut 65. Rotation of the nut 65about the axis of countershaft 63 is prevented by a pin 66 projectinglaterally from the nut into a slot 61 in the upper end of an arm 68con-. strained for rotation with the rockshaft Hi. When the nut 95 iscaused to move axially of the shaft 63 during rotation of this shaft, aside of the slot 61, depending upon the direction of axial advancing ofthe nut, will be pressed upon by the pin 66 to impart rocking movementto the arm 68, rock-shaft Hi, and the two arms upon the ends of theshaft i6 exteriorly of the casing I8.

Traveling nut 65, in addition to moving the rock-shaft l6, operates onecomponent 69 of a device H for controlling the electric circuit whichcontrols energization of the electric motor 21. This control circuitincludes spaced apart fixed electrical contacts I2 and I3 laterallyengageable by a movable contact 14. Fixed contacts '52 and 13 areconnected to the windings E5 of magnetic switch devices I6 and H byconductors i8 and 19; see Figs. 2 and 4. The movable contact 74 isconnected to the ungrounded side of the battery 29 by a conductor 8|.The terminals of the magnetic device windings l5 opposite to thoseconnected with the conductors l8 and 19 are grounded as indicated at 82in Fig. 4.

The motor 21 is assumed to be a direct current with a series-connectedfield winding. In Fig. 4 the motor armature is designated A and thefield winding is designated F. When the movable contact 14 engagescontact 72, current will flow from the battery through the conductor 8|,the closed contacts 12 and i4, and the wind-1 ing of the magnetic device16 to ground at 82, moving the armature 83 of such device for engagingcontact pairs 84 and 85. Thereupon current will flow from the ungroundedtermina1 of the battery through conductor 86, closed contact pair 84,conductors 81 and 88, motor field winding F, conductors 89 and 99,contact pair 85, conductors 9| and 92, and through armature the bellhousing 55 of the tractor body in registration with an opening 56 bymeans of cap screws 51. This opening 56 affords the entrance into thebell housing of the threaded front end portionthreads of the section 58and meshed therewith is normally held in an axially retracted positionAn eccentrically weighted portion 62 upon the hub of the pinion 59causes this pinion to resist rotation with the shaft 41 so that whenthis shaft is rotated'quickly in a counterclockwise direction, as viewedfrom its front end, the inertia of the weight 62 .and of the pinion 59will cause the threaded shaft portion 59 to rotate relatively to thepinion and thereby advance it forwardly into mesh with the starting ringgear 43 preparatory to driving the same for cranking the vehicle enginepursuant to continued rotation of the pinion. Employment of the helicalspring coupling 52 between the shafts 44 and 41 results in absorption ofsome of the shock which would otherwise be transmitted from the shaft 44to the starting pinion 59. Coupling spring 52 is also capable ofcompensating for slight misalinement between I the shafts 44 and 41.

motor armature shaft 34 to rotate clockwise as viewed from its frontend, thereby imparting counterclockwise rotation to'the gear 4| (whenthe gear 35 is meshed with the gear 4|) and to the threadedshaft ,63.counterclockwise r0- tation of the countershaft 63 will cause thetraveling nut 65 to move forwardly and to pivot the rock-shaft I6clockwise as viewed in Fig. 2. Operation of the motor and rocking of therockshaft IE will continue so long as the contacts 14 and 12 areengaged. Upon disengagement of the contacts 14 and 12, the magneticdevice 15. will deenergize and the contact pairs 84 and 85 separate forcausing the motor to stop. Upon stopping of the motor, the rock-shaft IEwill be held against rotation by the traveling nut 65 and thecountershaft 63. Driving of the motor 21 and of the rock-shaft in theopposite direction is accomplished by causing engagement of the contacts14 and 13. Upon such engagement of the contacts 14 and 13, current willflow from the ungrounded terminal of the battery through the conductor8|, contacts 14 and 13, conductor 19, and winding 15 of the electricmagnetic deductor 86, contact pair 95, conductors 91 and 89, the fieldwinding F (in the opposite directi'r to which the current flowed throughthis fielc winding when the magnetic device l6 was energized), theconductors 88 and 98, contact pair 96, conductor 92, and the armaturewinding of the motor to ground at 93. Because of the field winding ofthe motor having current pass through it in the opposite direction,.themotor will operate in the opposite direction: that is, its armature 34will rotate counterclockwise as viewed from the front, causing clockwiserotation of the gear and the threaded countershaft 63. Consequently therock-shaft I6 will be rocked counterclockwise as viewed in Fig. 2. Thisoperation of the motor and movement of the rock-shaft will continueuntil the contacts I3 and I4-are separated for deenergizing the magneticdevice I1 and opening the connections at 95 and 96 inthe motorenergizing circuit.

In addition to the motor-driven component 69 of the means II forcontrolling the control circuit contacts 12-13-14, there is a manuallyoperated component 99. Motor-driven component 69 is in the form of a camhaving an elongated slot l0l with parallel end portions I02 and I03which are offset vertically and connected at their inner ends by adiagonal slot portion I04. This member 69 is attached to the travelingnut by pins I05.

The manually operated component 99 of the electric circuit controllingdevice II is in the form of a cam follower comprising a pin I06 whichrides within the slot IN. This follower member 99 is ,.slidably mountedupon a horizontal rod I0! and when moved vertically will imparttransverse vertical movement to said rod. Opposite ends of the rod I01are pivotally connected to horizontal legs of bell-cranks I08 and I09,while a second horizontal rod H0 is pivotally connected with thevertical legs of said bell-cranks. Fixed pivots II2 are provided for thebell-cranks at the junctures of their legs; Movable contact 14 is fixedupon the rod I I0 so, that when this rod is moved endwise in onedirection or the other this contact will be moved from a neutralposition where.

it engages neither of the contacts 72 and I3 into position forcontacting one or the other thereof. These contacts 12 and I3, whilepermanently electrically connected withtheir respectively associatedconductors l6 and I9, are yieldably end-.

wise movablewi'thin small casings C so that the contact 74 can continuelimited movement endwise with the rod H0 after contact is made witheither of the so-called fixed contacts I2 and I3.

In the operation of the apparatus for controlling the "electric controlcircuit, should the operator desire to cause the motor 21 to operate inthe direction for pivoting the rock-shaft I6 clockwise as viewed in Fig.2, he will pull rearwardly upon the hand lever 23 in Fig. 1, causing theupper end of the lever 2| to move rearwardly and the lower end of thelever 2I to move forwardly and to thereby, through a link H3, move thecam follower member 99 forwardly, cam- ,ming this member 99 upwardlyalong the lower edge of the diagonal slot portion I04. Prior to thisupward movement of the member 99, its pin I06 occupied a mid positionbetween the ends of the diagonal slot portion I04, but this upwardmovement of the member 99 will impart upward movement to the rod I0"!and counterclockwise rotation of the bell-cranks I00'and I09 and endwisemovement of the rod IIO to the left, whereby the contact I4 is carriedinto engagement with the contact I2. When the contacts I2 and 14 arethus closed, the magnetic device I6 is energized for causing clockwiserotation of the motor armature shaft 34, as viewed from the front, and,as explained hereinabove-with reference to Fig. 4, this clockwiserotation of the armature shaft and of thegear 34 causes counterclockwiserotation of the gear 4| and the threaded countershaft 63 whereby thetraveling nut 65 will be advanced forwardly, causing clockwise rotationof the rock-shaft I6. Presently this movement of the traveling nut andof the cam plates 69 to the right will reestablish the cross pin I06 inthe mid. position within the diagonal slot portion I04 incident tomoving the rod I01 downwardly and pivoting the bell-cranks I08 and I09clockwise for withdrawing the contact I4 from the contact 12. When thisoccurs the motor 21 will stop after having driven the rockshaft I6 adistance corresponding to the distance the follower member 99 had beenadvanced lengthwise of the rod I01 and of the cam slot portion I03. Thislengthwise movement of the cam follower 99 is proportional to themovement of the, hand lever 23over its quadrant 25. Consequently, thedevice will operate to cause the motor 27 to rotate in a directioncorresponding to the direction of movement of the hand lever 23 andthrough a distance corresponding to the distance said hand lever ismoved.

Should the operator desire to cause the rockshaft I6 to rotatecounterclockwise, hewill move the hand lever 23 forwardly along thequadrant 25, imparting clockwise movement to the lever 2| and rearwardmovement to the follower member 99 whereby the pin I06 will be cammeddownwardly from the neutral mid position within the diagonal slotportion I04. This will move the rod I0! downwardly, pivoting thebell-cranks I08 and I09 clockwise and moving the rod IIO to the right,engaging the contacts I9 and '14. As explained above, engagements of thecontacts I3 and 14 causevthe motor to rotate in the direction whichincurs counterclockwise rotation of the rock-shaft I6. When this ensuingmovement of the rock-shaft I6 has attained an amount corresponding tothe movement of the hand lever 23, the cam slot IOI will havemoved-sufiiciently far relatively to the .pin I06 for reestablishingthis pin in the neutral mid section of the diagonal cam slot portionI04, moving the contact I4 back to its disengaged position between thecon- The amount of pivotal movement of the bellcranks I06 and I09 andconsequently the amount of movement of the contact I4 toward either ofthe contacts I2 and I3. is determined by the diagonal pitch and lengthof the slot portion I04. Subsequent to the pin I06 reaching either endof the slot portion I04, this pin I 06 is simply moved idly endwise inthe slot portions I02 or I03 without pivoting the bell-cranks'l08 or I09and without moving the contact 14. Movement of the cam follower pin I06more distantly into either of the cam slot portions I02 or I03, bymanually moving the hand lever 23 at such a speed that the pin I 06moves endwise of these slot portions I02 and I0! at greater speed thanthe cam plate 69 is advanced axially of the countershaft 63 by operationof the motor, results in correspondingly more distinct rocking of therockshaft I6 before the neutral mid portion of the diagonal cam slot canovertake the cam follower pin I06 for stopping the motor.

rearwardly out of mesh with the gear 4| and into mesh with theeountershaft gear 42 and thereafter the hand lever 23 is pulledbackwardly. This will cause the cam follower 99 to ride upwardly on thelower edge of the cam slot portion I04 to engage thecontacts 12 From theabove description it is apparent that this engagement of the contacts 12and 14 causes the motor armature shaft 34 to rotate clockwise wherebythe gear 42 and the shafts 44 and 41 will be rotated counterclockwise,as viewed from their front ends, for projecting the pinion .59 into meshwith the starter gear 43 on the engine fiy-wheel. of the motor 21 willcause the pinion to rotate the gear 43 for cranking the engine. Upon theengine commencing to run under its own power, the peripheral speed ofthe gear 43 and of the pinion 59 will exceed that of the shaft 41whereby the pinion will be spun counterclockwise ,upon the threadedshaft section 58 and projected out of mesh with the gear 43. Also uponstarting of the engine the operator will move the hand lever23'forwardly for moving the cam follower pin' I06 rearwardly anddownwardly to the neutral mid position in the slot portion I04 fordisconnecting the contacts 12 and I4.

Instead of employing the system illustrated in and 14,

Continued operation shaft, and upon the rock-shaft rocking a distanceclockwise corresponding to the manual clockwise movement of the arm N0,the contact l4 will have been moved out of engagement with the contact12* causing the electric motor and s i rock-shaft to stop. Manualmovement of the arm Ill) counterclockwise will carry the contact l3 intoengagement with the rock-shaft carried contact 14, causing energizationof the electromagnetic device 11 and counterclockwise rocking of therock-shaft it until such time as this rockshaft rocks a distancecorresponding to the manual movement of the arm H0, whereupon thecontact 14 will be carried out of engagement with the contact 13 forstopping the motor and the rock-shaft.

I claim:

1. In an electric power device for use upon an engine-driven vehiclehaving an engine-starting gear and a source of electric energy; thecom-' bination of an electric engine-starting motor energizable foroperation in reverse directions when selectively electrically connectedwith the Fig. 2 of employing fixed contacts 12 and 13 with.

a movable contact and a device H for controlling movement of the contact14 in opposite directions for selective contact with the contacts 12 and13, an arrangement may be employed similar to that illustrated in Figs.5 and 6. In this second form of electric circuit control, contacts I2and 13 corresponding respectively to the contacts 12 and I3 (hereinafterall reference characters with the suffix a designate parts respectivelycorresponding to those parts in the lower numbered figures which aredesignated by the same reference character without the suflix) arecarried upon an arm H0 mounted upon a casingwall boss Ill for rotationcoaxially with the rock-shaft I6 These contacts 12 and I3 are insulatedfrom one another and from said arm ill) by a block of insulatingmaterial H2 to which they are secured. Acontact I4 is carried by one ofthe rock-shaft arms l1. This contact 14 is suitably insulated from themetal arm=ll and is mounted therein for endwise movement within a recessH3. A spring 4 in the bottom of the recess reacts against the adjacentend of an insulating material carrier H5 for said contact l4 forconstantly urging this contact against the insulating body H2 or thecontacts 12 or l3 with'whichever it happens to be in registry. The outerfaces of the contacts 12 and 13*- a're flush with the outer face of theinsulating body H2 so the contact Hi' can slide freely over these faces.

"*Contacts 12 and I3 are for connection with tact l2 into engagementwith the contact 14.

when this occurs, the electromagnetic device 16 will be energized, asdescribed hereinlabove, for incurring the clockwise'rotation"of therockenergy source, an oppositely movable work member to be driven bysaid motor, driving connection means selectively establishable indriving relation between the motor and said starting gear and betweenthe motor and said work member, electric circuit means connectablebetween the source and motor to effect such energization thereof, saidelectric circuit means including'switch contacts closable in onecombination for causing motor operation in one direction and closable inanother combination for causing motor operation in the oppositedirection and a contact controlling means including cooperable elementsindependently movable for adjusting such contact controlling means incontrolling the closing and opening of said contacts, said contactcontrolling means having a neutral setting wherein neither combinationof contacts is closed, one of said elements being manually movable toadjust said controlling means for effecting closing of eithercombination of contacts and thereby incurring ensuing movement of saidwork member when the driving connection is established between the motorand said work member, and connecting means connecting the other of saidelements with said work member for movement therewith in the directionand amount to reestablish the neutral setting coincidently with suchwork member moving an amount correlated with the amount ofmanualmovement of the one element in the direction effecting the contactclosing adjustment.

2. In an electric power device for use upon an engine-driven vehiclehaving an engine-starting gear and a source of electric energy; thecombination of an electric engine-starting motor energizable foroperation in reverse directions when selectively electrically connectedwith said energy source, an oppositely movable work member, drivingconnection means selectively establishable in driving relation betweenthe motor and starting gear or between the motor and said work member,electric circuit means conneetable between the source and motor toeffect energization of the motor and including switch means susceptibleof one manipulation to connect the circuit for causing motor operationin one direction and suscept ible of another manipulation to connect thecircuit for causing motor operation in the opposite direction, andswitch operating means including cooperable independently adjustable camand cam follower elements, said elements having a neutral settingwherein said switch operating tric circuit connections for controllingaaiaeoa the driving connection isestablished between the motor and saidwork member, and the other of said elements being connected with saidwork member for movement with the ensuing movement thereof and in thedirection and amount to reestablish the neutral setting upon such membermoving an amount correlated with the posed transversely of suchintermediate body portion, a reversibly drivable electric motor, meansfor selectively establishing a driving connection between the motor andthe rock-shaft or the starting gear driving shaft, an electric circuitfor energizing said motor, and circuit connecting means comprising acomponent manually movamount of manual adjustment of the one element.

3. In a tractor having a forward body portion carrying an engine and astarting gear therefor, a rear body portion with traction wheels, and anintermediate body portion; an electric power device carried by theintermediate body portion, said power device including an electric motorenergizable for operation in reverse directions, elecion of said motorand selectively adjustable between a neutral setting incurring motorquiescence and alternative drive settings incurring motor drive inrespective opposite directions, a rock-shaft mounted on and transverselyof the tractor at the intermediate body portion, driving meansadjustable for selectively drivingly connecting the motor with therock-shaft and the engine starting gear, and circuit adjusting meansmanipulatable from a neutral condition wherein the electric circuit isset in neutral into alternative conditions to respectively establish thealternative circuit settings, a control member manually operable toobtain any of the circuit adjusting means conditions, and automaticcontrol means operable coordinately with movement of th rock-shaft toreestablish the neutral condition of said circuit adjusting meansincident to the rock-shaft rocking in a direction and amount correlatedwith the direction and amount of movement of the manual control memberin causing such rocking.

4. In a tractor having a forward body portion carrying an engine with astarting gear, a rear body portion with traction wheels and anintermediate body portion; an electric power device comprising a casingmounted on the intermediate tractor body portion, a starting geardriving shaft in said casing, a driving connection between said shaftand the starter gear, a rock-shaft journaled in said casing, areversibly drivable electric motor mounted on said casing, means forselectively establishing a driving connection between the motor and therock-shaft or the starter gear driving shaft, an electric circuit forenergizing said motor, and circuit connecting means comprising acomponent manually movable to selectively establish connections of saidcircuit incurring drive of the motor in either direction,

and said circuit connecting means also comprising a component movablecoordinately with said rock-shaft to disconnect the circuit incident tothe rock-shaft rocking in a direction and amount correlated with thedirection and amount of movement of the manually-moved component incausing such rocking.

5. In a tractor having a forward body portion carrying an engine with astarting gear, a rear body portion with tractionwheels and anintermediate body portion; an electric power device carried by saidintermediate body portion and comprising a starter gear driving shaftextending longitudinally of the tractor and drivingly connected withsaid starter gear, a rock-shaft disenergizaable to selectively establishconnections of said circuit incurring drive of the motor in eitherdirection, and said circuit connecting means also comprising a componentmovable coordinately with said rock-shaft to disconnect the circuitincident to the rock-shaft rocking in a direction and amount correlatedwith the direction and amount of movement of the manually-movedcomponent in causing such rocking,

6. In an auxiliary power device for a tractor having a source ofelectric energy and an engine- 'starting gear, a starting gear drivingshaft drivrock-shaft to disconnect thecircuit incidentto.

the rock-shaft rocking in a direction and amount correlated with thedirection and amount of movement of the'manually-moved component incausing such rocking.

7. In an auxiliary power device for a tractor having a source ofelectric energy and an enginestarting gear, a starting gear drivingshaft journaled on the tractor for rotation about a fore and aft axisand drivingly connected with said starting gear, a rock-shaft journaledon the tractor for rocking motion about an axis extending transverselyof the tractor, a rock-shaft driving arm with which the rock-shaft isconstrained to rock, a traveling nut drivingly associated with said arm,a threaded shaft journaled in parallelism with the starting gear driveshaft and meshed with said nut to advance or retract the same accordingto the direction such shaft is driven and to correspondingly rock therock-shaft in one direction or the other, a reversibly drivableelecdriving connection between the motor and either of said shafts, anelectric circuit connectable between the electric energy source and themotor for energizing the latter, and circuit connecting means comprisinga component manually movable to selectively establish connections ofsaid circuit incurring drive of the motor in either direction, and saidcircuit connecting means also comprising a component movablecoordinately with said rock-shaft to disconnect the circuit incident tothe rock-shaft rocking in a direction and amount correlated with thedirection and amount of movement of the manually-moved component incausing such rocking.

8. In a tractor having a forward body portion carrying an engine with astarting gear, a rear body portion with traction wheels and anintermediate body portion; an electric power device comprising a casingmounted on the intermediate tractor body portion, a starting geardriving shaft journaled in said casing for rotation about an axisextending fore and aft of the tractor, universally articulatemeansdrivingly connecting said shaft with the starting gear, a rock-shaftjournaled in said casing transversely of the starting gear shaft, arock-shaft driving arm in said casing and with which the rock-shaft isconstrained to rock, a traveling nut drivingly associated with said arm,a threaded shaft journaled in the casing in parallelism with thestarting gear driving shaft and meshed with said nut to advance orretract the same according to the direction the threaded shaft isrotated and. to

correspondingly rock the rock-shaft in one direction or the other, areversibly drivable electric motor mounted on said casing, means in thecasing for selectively establishing a driving connection between themotor and either of said shafts,

plying electric energy to the motor for energizing the same, and circuitconnecting means comprising a component manually movable to selectivelyestablish connections of said circuit incurring drive of the motor ineither direction, and said' circuit connecting means also comprising acomponent movable coordinately with said rock-shaft to disconnect thecircuit incident to the rock-shaft rocking in a direction and amountcorrelated with the direction and amount of an electric control circuitconnectable for supmovement of the manually-moved component in causingsuch rocking.

9. In an electric power. device for use upon an engine-driven vehiclehaving an engine-starting gear and a source of electric energy; thecombination of an electric engine-starting motor energizable foroperation in reverse directions when selectively electrically connectedwith the energy source, an oppositely movable work memher to be drivenby said motor, driving connection means selectively establishable indriving relation between the motor and said starting gear and betweenthe motor and said work member, and electric circuit means connectablebetween the source and motor toeifect such energization thereof, saidelectric circuit means including switch contacts closable in onecombination for causing motor operation in one direction and closable inanother combination for causing motor operation in the oppositedirection.

10. In an electric power device for use upon an engine-driven vehiclehaving an enginestarting gear and a source of electric energy; the

combinationof an electric engine-starting motor energizable foroperation in reverse directions when selectively electrically connectedwith the energy source, an oppositely movable work mem- (ill 11. In anelectric power device for use upon an engine-driven vehicle having anengine-starting,

establishable in driving relation between the motor and said startinggear and between the motor and said work member, and electric circuitmeans connectable between the source and motor to efiect suchenergization thereof, said electric circuit means including switchcontacts closable for causing motor operation.

, 12. In an electric power device for use upon an engine-driven vehiclehaving an engine-starting gear and a, source of electric energy; thecombination of an electric starting motor energizable for operation whenelectrically connected with the energy source, a work member to bedriven by said motor,- driving connection means selectivelyestablishable in driving relation between the motor and said startinggear and between the motor and said work member electric circuit meansconnectable between the source and motor to effect such energizationthereof, said electric circuit means including switch contacts closablefor causing motor operation, and means operable in response tomovementof said work member for disconnecting said circuit means.

13. In an electric power device for use'upon an engine-driven vehiclehaving an enginestarting gear and a source of electric energy; thecombination of an electric starting motor energizable for operation whenelectrically connected with the energy source, a work member to bedriven by said motor, driving connection means selectively establishable'in driving relation between the motor and said starting gear andbetween the motor and said work member, electric circuit meansconnectable between the source and motor to effect such energizationthereof, said electric circuit means including switch contacts closablefor causing motor operation, means advanceable for closing saidcontacts, and means operable responsively to ensuing movement of saidwork member and to the amount of advancement of said contact closingmeans for disconnecting said circuit.

14. In an electric power device for use upon an engine-driven vehiclehaving a source of electric energy; the combination of an electric motorenergizable for operation when electrically connected with the energysource, a work member to be driven by said motor, driving connectionmeans for driving the work member from said motor, electric circuitmeans connectable between said energy source and the motor to efiec'tsuch energization thereof, said electric circuit means including meansfor establishing its said connection between the motor and source, meansmanually advanceable for operating said circuit establishing means, andmeansoperable responsively to ensuing movement of said work member andto the amount of advancing of said manually advanceable means forinterrupting the establishment of said circuit.

CARL W. MOTT.

